Taping trowels



May 3, 1960 G. N. VERNON 2,934,936

TAPING TROWELS yFiled July 16. 1956 2 Sheets-Sheet l May 3, 1960 Filed July 16. 1956 G. N. VERNON TAPING TROWELS 2 Sheets-Sheet 2 INVENTOR for both the first and the finishing coats.

2,934,936 TAPING TRoWELs George N. Vernon, Sebastopol, Calif. Application July 16, 1956, Serial No. 598,213

2 Claims. (Cl. 72-136) This invention relates to trowels, especially to trowels for taping sheetrock or gypsum board or similar panel units, and is more particularly concerned with trowels .for spreading taping cement over tape in the taping of joints between panels in thel construction of houses or other buildings.

In the application of sheetrock, gypsum board and other plied over the joints and the tape with the cement cover- 'ing the tape and extending substantially beyond each edge thereof.

Heretofore, it 'has been the practice to apply the taping .cement with an ordinary trowel, the trowel being disposed at a slight angle to the wall surface to build up a 'layer of cement with bevelled edges and having a maximum thickness substantially along the center line of the tape. -As in Plastering walls, the cement is usually applied in at least two layers, a base layer and a finishing layer. In applying the cement over the tape, the usual fiat trowel with straight edges is employed, the trowel lbeing positioned ata slight angle to the plane of the wall board with a corner o f the trowel bearing against the wall board laterally of the edge of the tape, operating first along one side and then along the other ,side of `the tape. Obviously, even with the most skilled operators, this process results in an uneven taping job, especially 'when applying the finishing coat or layer which is relatively thin. Consequently, it is usually necessary to sand over the taping cement to provide a thin, uniform, smooth taping job that is not conspicuous, even to the casual observer, and this sanding operation may be necessary Moreover, the gcorner of the trowel bearing against the wall board frequently marks-or scores the board.

Having in mind the defects of the prior art apparatus,

tit, is the primary object of the present invention to pro- 'vide `a taping trowel whereby the taping cement may be :applied in easily regulatable columns as well as in symmetrical relation to the tape.

Another object of the invention is to provide a taping 'trowel whereby successive coats of cement of dierent lwidths and thicknesses may be applied to the tape under relatively easy manipulation of the trowel.

arent 2 Yet another object of the invention is to provide a taping trowel having simplicity of design, economy of construction and eiciency in operation.

The novel features that are considered characteristic i of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and its method of operation, together with additional objects and advantages thereof, will best be understood from the following description of specific embodiments when read in connection with the accompanying drawings, wherein like referenceV characters indicate like parts throughout the several figures and in which:

Fig. 1 is a top plan view of one embodiment of a trowel in accordance with the present invention;

Fig. 2 is a side elevational view of the trowel shown in Fig. l;

Fig. 3 is an end elevational View as observed from the right of Fig. 2; Y

Fig. 4 is a side elevational view of the trowel provided with a modified form of handle;

i'Fig. 5 is a plan view showing the improved trowel in use;

Fig.6 is an outer plan view of a modified embodiment of the invention;

Fig. 7 is a side elevational view ofthe trowel shown in Fig. 6;

Fig. 8 is a cross-sectional view as observed in the plane of line S-S of Fig. 7, and

Fig. 9 is a view corresponding to Fig. 7 showing th trowel provided With a modified form of handle.

Referring now in detail to the drawings, specifically to Figs. l to 3 thereof, an improved taping trowel in accordance with the present invention comprises a blade 1l) which is of generally rectangular form as indicated in Fig. l and is of relatively thin sheet metal. An elongated rib 11 is disposed substantially in the longitudinal center line of the blade and suitably rigidly secured thereto as by rivets 12. An arm 13 unitary with the rib 11 projects upwardly therefrom adjacent one end thereof and is slightly inclined toward the other end thereof. A cylindrical shank 14 projects from said arm 13 toward the other end of the rib and a cylindrical handle 15 is supported on the shank by any suitable means as by a nut 16 or a heading over of the shank. The handle 15 is thus disposed substantially centrally of the blade 10 and in sufficiently spaced relation thereto as to provide hand room between the blade and handle.

A predominating feature of the trowel, in accordance with the present invention, resides in the formation of the blade 19 in an arc longitudinally of the blade, as is clearly indicated in Fig. 2, that is, the working surface 17 of the blade is longitudinally, upwardly arched whereby only the opposite ends thereof rest on a plane surface. Furthermore, the opposite side edges 18 and 19 of the blade 10 include recessed or inwardly curved edge portions 18 and 19 which are symmetrical to the transverse center line of the blade. The curved edge portion 19 is longer than the curved edge portion 1S and the edge portion 19' is deeper than the edge portion 18 with respect to corresponding otherwise straight edges 18 and 19, as is indicated by the broken lines Vin "Fig. 1. The opposite end edges 23 and 24 of the blade 10 are straight and square with the side edges 18 and19.

In Fig. 4 is shown a modified form of handle structure wherein the rib 11' is provided with a pair of longitudinally spaced, upwardly projecting arms 2t) whose upper ends are rigid with a longitudinal shank 21 to which a twowpart handle 15 is connected, as by rivets 22. This form of handle serves to strengthen and reinforce the blade 1@ and maintain the curvature thereof. Other forms of handles may, of course, be attached so far as the operative efficiency of the blade is concerned. The operation of the improved trowel is illustrated iu Fig. 5 wherein W indicates a wall formed of juxtaposedl wall boards having a joint I therebetween. In the taping process, a quantity c of cement C is spread over the joint I in an excess of the'arnount required to fill all of the cracks. A tape T, which comprises a strip having a plurality of small holes therethrough, is then placed over the joint I and` the cement coating c and a straight end edge 23 or 24 of the trowel is drawn lengthwise over the tape T to squeeze out as much of the excess cement `as possible. While the coating c is still wet, the tape T is covered with a first coating c' of cement which is left to dry. After the coating c is dry, a second cement coating c, and possibly a successive third coating c", are applied over the first coating c. ATo apply the first coat c of cement, a quantity of cement C is spread over the tape T in the usual manner and the trowel is then placed with its edge y18 against the wall W at an angle to the wall and with the recessed portion 1S' astraddle and substantially symmetrical with respect to the tape T. With the trowel transverse the tape, the trowel is then moved longitudinally of the tape T, the recessed portion 18 leaving a smooth, bevelled edge, uniform layer or cement coating c'. To apply the second coat c, the operation is repeated with the edge 19 of the blade 1) bearing on the wall W with the recess 19' substantially symmetrically astraddle the first coat c'. Normally, the third cement coating c'" is not added but to apply it, the blade 10, which is slightly flexible, is placed with less pressure against the wall W with its Working surface 17 straddling the second coat c.

The curvature of the working surface 17 of the blade facilitates the operation of the recessed edge portions 18 and 19 and enables these edge portions to smooth rather than merely scrape on the excess cement. The trowel is shown in Fig. 5 in the application of the second coat c" and in which operation the cement C, disposed within the concave side 17 of the trowel, is caused to flow through the space provided by the inwardly curved edge portion 19 of the trowel edge 19, the blade 10 being slightly tipped in the application of the cement coating. In the application of the coatings, as shown in Fig. 5, the trowel is drawn in the direction of the arrows.

While the trowel disclosed in Figs. l to 4 is adapted for use on plane walls or ceilings, the trowel shown in Figs. 6 to 9 is adapted for use in the taping of corners between walls or between a wall and a ceiling. This corner trowel comprises a blade 25 including a pair of `right angularly disposed wings 25a diverging substantially at right angles from a slightly rounded apex 26. A right angular rib 27 is rigidly secured to the blade 25 and this .rib is subtended by a shank 28 which braces the wings 25a of the blade 25 and to which a two-part handle 29 is secured, as by rivets 30. From Fig. 7, it will be seen that the handle 29 is so disposed as to provide suicient hand room between it and the blade 25. In the modified construction shown in Fig. 9, a single arm 33 extends from the apex 26 in bisecting relation to the angle between the blade wings and is formed with a T-head 34 to which a handle 35 is rigidly secured, as by rivets 36. Other forms of handles may be used within the spirit of the invention.

In accordance with the present invention, the wings edge 31 of the blade includes portions 31a converging 4Afrom the opposite end portions of the blade 25 toward '4 the apex 26, and at relatively small-angles to the broken line which is normal to the opposite ends of the blade. The opposite edge 32 includes "portions 32a converging from the opposite end portions of the blade 25 to the apex 26 at relatively small angles to the broken line which is normal to the opposite ends of the blade, these latter angles, however, being greater than the first named angles.

In the use of the corner trowel, the apex 26 thereof is disposed within a corner and the opposite ends of the blade 25 engage adjacent walls, or aewall and a ceiling, and the blade is slightly tipped transversely for exudation of the cement beneath one edge thereof. .By the provision of the angle edges of the blade, as desired, less tipping of the trowel is required for a' given flow of cement from beneath the trowel into .covering relation to the tape.

Although certain specific embodiments of the invention have been shown and described, it is obvious that many modications thereof are possible. The invention, therefore, is not to be restricted except insofar as is necessitated by the prior art and by the spirit of the vappended claims.

What is claimed is:

l. A taping trowel comprising an elongated blade of substantially rectangular form in plan, said blade being arched throughout its length, and a blade manipulating handle secured to the convex surface of said blade, said blade including opposite elongate side edgesv each having an elongate shallow recess converging to a point substantially centrally thereof with the recess in one edge slightly deeper and longer than the recess in the other edge, said recesses extending over a major portion of the length of each side edge, whereby the edge with the shallower recess may be used for applying an undercoat and the edge with vthe deeper recess may be used for applying an outercoat.

2. A corner taping trowel comprising a blade including a pair of right angularly disposed wings converging to an apex, and a handle secured lto said blade and disposed within 'the angle of said wings, said wings being plane and having opposite straight end edges and opposite side edges at least portions of which converge from said end edges to said apex to form shallow recesses in the side edges of said blade, said recesses extending over a major portion of the length of each side edge, the side edges at one side of said blade being disposed at an angle to the longitudinal center line of the'blade different from the angle of the side edges at the opposite side of said blade relative to said longitudinal center line to provide one of said recesses with a greater depth than the other, whereby the edge with 'the shallower recess may be used for applying an undercoat and the edge with the deeper recess may be used for applying an outercoat.

References Cited in the tile of this patent UNITED STATES PATENTS 

